Democracy activist Sunny Cheung Kwan-yang has applied for asylum in the United States a year after fleeing the SAR because of the enactment of the national security law.

He posted an update on his Facebook page on Monday to say he had submitted a refugee claim with the US government.

Cheung, 25, along with fellow activist Nathan Law Kwun-chung, failed to show up in September at a court hearing to face charges relating to last year's June 4 vigil.

He announced on Facebook later that day that he had fled to an undisclosed location and cited fears of being followed and threats to members of his family.

"Since leaving Hong Kong last August I have been attending various forums and closed-door meetings with government officials and activists from the United States, the United Kingdom, Australia, Japan, Korea and Taiwan to talk about the crisis in Hong Kong," Cheung wrote on Monday.

He added: "I have decided to live in the United States and continue my work."

Subject to an arrest warrant, he said his involvement in lobbying Washington to pass the Hong Kong Human Rights and Democracy Act was the major reason for him to leave.

He has been admitted to a master's program at Johns Hopkins University's School of Advanced International Studies.

Cheung also said exiles he knew did not aim to build a new Hong Kong overseas. Rather, he said, they would like to return.

He added: "There is only one Hong Kong for me."

He also revealed he had limited money when he fled the SAR and thanked people who have helped him.

Cheung was spokesman for the Hong Kong Higher Institutions International Affairs Delegation, which was disbanded last June 30.

He had been to many countries during the unrest in 2019 and lobbied the United States to impose sanctions on Hong Kong and mainland officials as well as push passage of the Hong Kong Human Rights and Democracy Act.

He was charged with taking part in an unauthorized assembly together with 25 other democrats at Victoria Park on June 4 last year.

Runaway activist Sunny Cheung readies for stay in US